Conventionally, there is known a technique to monitor information about driving states obtained by using an internal sensor, and to record the information about the monitored driving states in a longer time span before and after the time when an abnormal event or an event close to an abnormal event has occurred in factors (a steering wheel, a brake, an accelerator, an engine itself, and the like) related to the driving (see Patent Document 1). By this conventional technique, information before and after the time when an event diagnosed to be abnormal has occurred are recorded as vehicle behavior log data. This is because a memory device is required to have vast memory capacity to record all information about driving, which is detected by various sensors, as vehicle movement log data. In this conventional technique, maintenance information of a vehicle is outputted, which information is obtained by analyzing the recorded vehicle movement log data.    Patent Document 1: JP-A-10-24784